Pick Some
<esp-pick-some>
Component for selecting multiple options from a list of options.
Initial state (HTML)
Set the initially selected items using the selected attribute
on the esp-picker-item elements:
Initial state (programmatic / pickerItems)
When populating options via the pickerItems property (common
in Lit templates that load data from an API), set selected: true
on items that should be pre-selected. The picker automatically
detects items with selected: true and renders them as chips:
const allTopics = await fetchTopics();
const mySelectedIds = new Set(user.topicIds);
picker.pickerItems = allTopics.map(t => ({
text: t.name,
value: t.id,
selected: mySelectedIds.has(t.id),
}));
This works with all modes — plain, typeahead (local), and
typeahead (remote via fetchItems). The component reads the
selected flag from pickerItems during willUpdate() and
populates selectedItems automatically. Do not separately
assign selectedItems — just set selected: true on the
items in pickerItems.
Typeahead (local filtering)
Add the typeahead attribute to let the user type to filter
the option list. The input becomes editable and the picker
switches to a filter icon on focus:
Typeahead (remote filtering)
Set the fetchItems property to a callback that returns
matching items from a server. The picker debounces input
(300 ms by default) and shows a loading indicator while
the request is in flight. Use the provided AbortSignal
to cancel stale requests:
Add new value
Set the addNewValue property to a callback that creates
a new picker item from the typed text. When the user types
a value that does not match any existing item, the dropdown
caret becomes a plus icon. Clicking the plus (or pressing
Enter) invokes the callback and adds the returned item as
a checked selection:
Attributes
<esp-pick-some> has the following attributes:
values
values has a default value of undefined.
The values of all currently selected items.
typeahead
typeahead has a default value of false.
When true, the picker input becomes a typeahead search field. The user types to filter the option list.
debounce-ms
debounce-ms has a default value of undefined.
Debounce delay in milliseconds for typeahead input. Defaults
to 0 for local filtering and 300 for remote fetching.
name
name has a default value of "".
The name used when the picker participates in a <form>.
required
required has a default value of false.
When true, a selection must be made before the form can be submitted.
required-message
required-message has a default value of "".
A custom message to display when the picker is required but no
selection has been made. Defaults to
"Please select an option." for esp-pick-one and
"Please select at least one option." for esp-pick-some
when not set.
disabled
disabled has a default value of false.
When true, the picker is disabled and cannot be interacted with.
pickerItems
pickerItems has a default value of [].
The list of picker items to display in the picker.
It can either be bound programmatically or computed
from the child esp-picker-item elements.
placeholder
placeholder has a default value of "Choose...".
The text that is displayed in the input prompting the user to choose options.
width
width has a default value of "".
An explicit width for the picker trigger. Accepts any valid
CSS width value (e.g. "5em", "80px"). When set, the host
element is sized to this width while the dropdown menu is
allowed to be wider to accommodate longer items.
Methods
<esp-pick-some> has the following methods:
focus
Focus the picker.
validate
Re-run constraint validation and dispatch validity-changed.
checkValidity
Check whether the current state is valid (delegates to ElementInternals).
traverseToClosest
Traverse up the DOM tree to find the closest element that matches the selector. This method is aware of shadow DOM boundaries and will traverse through them to find the element.
Events
<esp-pick-some> emits the following events:
value-changed
value-changed is of type CustomEvent<PickerItem[]>.
Fired when the user adds or removes a selected picker item.
CSS Properties
<esp-pick-some> has the following CSS properties:
--esp-field-background
Background color of the shared field shell. Defaults to var(--esp-color-layer-2).
--esp-field-border-color
Border color of the shared field shell. Defaults to var(--esp-color-border).
--esp-field-border-width
Border width of the shared field shell. Defaults to 1px.
--esp-field-text-color
Text color used inside the shared field shell. Defaults to var(--esp-color-text).
--esp-field-hover-bg
Hover background color of the shared field shell. Derived from --esp-field-background.
--esp-field-focus-bg
Focus background color of the shared field shell. Derived from --esp-field-background.
--esp-field-focus-shadow
Shadow color used for shared field focus treatment. Defaults to var(--esp-color-shadow).